129 hydro issue
 

So here is what transpired in post before I was asked to move post and rightfully so...

Original question,
Maybe one of you Hydro guys can tell me about this. I started it up. Raised the idle to about half I touched the hydro control forward and WOW.. Damn thing did a wheelie. Glad I didn't push it all the way. I tried this a few more times and man that thing is way more responsive and touchy than my 1211. No funny noises, its responsive in reverse also. It really really surprised me though. It feels fine as I said. If I slowly engage it and go slowly faster and faster I can control the response. Is this normal on these older hydros?

My findings,
So, from the bolts under seat and foot rests it actually looked like no one has ever had it apart to mess with trunnion. That's the good news. Looking at trunnion I do see 2 corners on same side have very slight wear. Is this enough to cause the wholeshot wheelies I'm getting ? From what I was reading wear like this usually causes speed fluctuations and coasting type issues.

Response to findings and last post.. Any help would be appreciated


Originally Posted by cooperino View Post
So, from the bolts under seat and foot rests it actually looked like no one has ever had it apart to mess with trunnion. That's the good news. Looking at trunnion I do see 2 corners on same side have very slight wear. Is this enough to cause the wholeshot wheelies I'm getting ? From what I was reading wear like this usually causes speed fluctuations and coasting type issues.
No... it shouldn't be causing issues like that.
Maybe the friction nut is adjusted too tight on the hydro lever....?
__________________
Jonathan
"They say money doesn't buy happiness....... but it does buy Cub Cadets, and Cub Cadets make me VERY happy!"

Runners: 1050, 1811, 185LB, JD 317
On the "back burner": 2-71's, 1250DS, 1000, 582, 682, 982, JD 318.
I have over 30 implements/attachments! IH, Cub Cadet, Brinly, Agrifab, and more!

Quote:
Originally Posted by cooperino View Post
I just went out to garage and with the engine off the lever actually moved very freely. When running you feel what I think is normal resistance. Not sure how I missed this. Before but I see the fan is long gone off the shaft. Could years of running this way be what's causing my issue now from prior over heating? Either way I'll be doing some welding ... The safety switch lever is also gone lol. I've been hot wiring the coil to start it. I assumed the safety switch itself was bad and almost ordered one. Mine is good tho.
Have you ever driven a left hand hydro tractor? They're a bit different. Not as much motion in the handle, so you have to move it differently. You sure you're not just moving it too fast? Nothing you are saying sounds out of line.... other than you popped a wheelie. Which I can honestly say I have never done on a CC. No, a lost fan and an overheated hydro would not cause the issue. If it had been overheated, it would be weak, not aggressive.

I don't know what to tell you. Check all the linkage out, see if everything is moving like it should. Make sure the cam plate and the swashplate control arm move independent of each other. You should see the springs compress when you move the dash lever and it starts to move. Might not be much, but the two plates should be free from each other.

As far as the safety switch, just put a jumper wire in it for now until you get it fixed. Quit jumping the solenoid. Tape the switch on or something....

Go start a thread on it too. This is just supposed to be a "show and tell" thread, not a question thread.
__________________
Jonathan
"They say money doesn't buy happiness....... but it does buy Cub Cadets, and Cub Cadets make me VERY happy!"

Runners: 1050, 1811, 185LB, JD 317
On the "back burner": 2-71's, 1250DS, 1000, 582, 682, 982, JD 318.
I have over 30 implements/attachments! IH, Cub Cadet, Brinly, Agrifab, and more!

Ok so to answer Jonathan's questions. No have not driven left hand hydro but how different should it feel from a 1211? Power and ratios can't be that drastic can they? Im not ramming the lever forward quickly or anything like that.

I checked all the linkage and everything seems to move freely and easily.

Quote J-Mech
As far as the safety switch, just put a jumper wire in it for now until you get it fixed. Quit jumping the solenoid. Tape the switch on or something....

LOL.. Ill keep jumping the solenoid all I damn want because Im not using a screwdriver crossing the post and melting the crap out of them.. Long time mechanic remember?? I have the proper tools to do what im doing. While Im welding the trunnion "might as well since I have it apart" I will also weld the safety switch lever. I dont want to jumper it because god forbid I forget to take the jumper out my son could come along and start it...

Heres the correct tool for jumping solenoid.

I really do appreciate your help tho Jonathon and thank you.:beerchug:

Ratio's are very different. Power is the same. Hydro's are the same. Linkage is different.


Well, again.... I don't know. Still sounds like operator error. The pic of the springs look fine. Sure it has some wear, but nothing that bad. Spring isn't broken is it? Are both springs present?


Put a jumper wire in. You can remove the key to keep the kid from starting it. It does have a key doesn't it??

I dont know about the operator error part. I have driven lots of hydro type vehicles and tractors and never had one react like this. If you read my first post what im saying is i barely touch this thing and it moves. Any tiny bit more than barely moving it and it takes off hard!.... I know how things are built and I doubt Cub would ever put out something that was suppose to feel this herky jerky. You may not trust my judgment but I would love to see your reaction if you drove this thing.

Yeah.. it has a key.. Same damn universal key his tractor has.. Crazy Jon, Not stupid ;)

I've found the "responsiveness" of the hydro to vary on my various hydro tractors. The 149 is pretty quick to respond, the 1650 is a bit slow. I'm not sure if there is a difference due to relief valves or some other internal function.

Moving the trunnion arm tilts the swashplate in the hydro, changing the amount and direction of fluid from the drive pump to the driven pump.

Have you changed the fluid in the rear end? Is it proper spec'd fluid? If it were very low viscosity, it might react differently than a more viscous hydraulic fluid.

Maybe there is even water in there? Heaven forbid.

Just trying to think about what might be different about this tractor for you...

Post a video or something. No, it shouldn't take off like a shot, but like in how much movement? Like 1/4"? 1"? How far? On the right hand dash lever models, you have to move most of them a good 1" or more for it to do about anything. Not so much on the others.


It shouldn't have an Indak key switch. Should have an IH key switch. Better make sure it's wired right.

Yes, I would weld up them grooves in the trunnion arm. That could be your problem or at least part of it. You see, them end caps on the springs get caught in the groove then abruptly comes out as you engage the lever, causing a quick response.

Thanks all, I will be draining the fluid tomorrow I hope. It still has whatever the PO had in it and I thought about that actually as being an issue..

Jon, Yeah if i move it about a half an inch in sort of not slow but not fast motion. Thats when it gets jerky. Any faster and or farther than that man it gets a little scary. Im not timid. My pro stock drag car runs 8's and will get nasty if you come out of the hole to hot but Im not use to this on a tractor lol.

It seems like all the responsive movement is in the first inch even though the spectrum of the lever itself seems to be more like 3 inches. A relief valve might really make sense hear. It feels like I am getting full hydraulic pressure very quickly.

Ill look more tomorrow. Thanks for the input all.

Guys, there is NO system relief valve on these hydro's. There are check/charge valves.... you know, the ones that always leak. But they are NOT relief valves. There is a relief valve on the charge pump. If it was set ridiculously high, it could make it more responsive.... but it would have to be stupid high. Like 1000 psi or more. The charge pump can't handle much more than 1000 PSI. If it is a ported pump, there is an implement relief valve also. It is separate from the other one. But NO system relief valve.

So, if you move the lever over 1" it gets stupid huh..... have you taken the tunnel cover off and watched the linkage move while you move the lever yet? Got a video for us yet?

Tunnel cover is off. I have moved lever with engine off. I can do it with it running but that won't change how the linkage moves. The two plates move independently and neither show any sign of heavy wear or being excessively tight or loose. Jon, I will put it this way. What i did to try to control it is this.. I left the unit at idle, then i moved the lever to forward slowly as far as it would go. I had better control of speed by using throttle to make go faster than the hydro lever. By time I got to full throttle I was well over the top speed of any GT I have ever owned. Top speed to the point that I could only do this on flat pavement to maintain control of the tractor.. Way faster than I feel this tractor should really go. Is it possible that the charge pump relief is broken internally and wide open?

You may be over thinking this issue! Is the hydrostat lever on the dash very easy to move? It usually is loose on these old tractors. There are two style of control linkage. One is easy to adjust...the other needs new parts. If the linkage is loose it can can cause the the speed to be eratic. If you find that as the tractor is moving and it speeds up by itself when you let go of the handle...it is not possessed but the linkage is loose and needs attention.:beerchug:

No, that is not possible.
The 129 should run about 10mph. Shouldn't be any faster than your 1211.
Only way it can be faster than it was from the factor is if someone took the hydro apart and ground the back side of the swashplate off. It bottoms out against the case at full speed... in forward and reverse. Only other way it can be sped up if larger rear tires. All the ring and pinion sets are the same speed.

I still think you just haven't got used to the left hand hydro......:biggrin2:
But I'll give in if you find something wrong. I like giving you a hard time.

Thanks for the input.. Its really not erratic at all. It does the same thing every time. I watched the lever for looseness and the rod that runs down to move linkage. All moves freely but not loose. I would not call what I am getting erratic. Its more a feeling of going from little speed or normal speed to wide open but then if i push farther it goes even faster. The top end on this thing the way it is right now is so fast you cant control the steering which is not great but is better than the one I mow with. The engine is not over revving so my thinking was hydro. SO the question is if i turn the hydro at 3000 rpm what in the hydro controls the top end as far as speed goes? I would have thought relief valve but J-mech says there is only one on charge pump. If that one is wide open will it make the tractor over speed? I can control the speed but really have to concentrate on that lever to do so. Im serious.. anyone out there with a k301 hydro wanna race?? Im bone stock and I bet I smoke ya.. LOL.. im joking but its sorta the truth.

We posted at the same time..... I answered your post #15 questions in post #14 because I'm that good. :biggrin2:

At 10 mph I would have control of this tractor. Its higher than that. I know its possible because I'm living it. No one has had this hydro apart unless they really good at hiding wrench marks on bolt heads.

Put some slicks on it...a cheap set of flame decals and go hang around the local race track. Who knows you may race an old rustang and win!:biggrin2:

I bet it isn't over 10 mph. It was only rated at 8. You sure that engine is running 3600? :bigthink:

Maybe you better back it off if it's too much for you. Detune that pig. Don't want you to rip your dress getting on and off of it. :HeeHee:

Or you can race this guy! Yee Haw :biggrin2:

Lmao.. IKR lol. Its sorta baffling I agree but I know something is a miss. These machines were meant for torque not speed. Seems this one has both for some unknown reason but I will get to the bottom of it. Btw. Stock size tires. Might even be original tires for all I know. I also sought the old man and original owner asked someone to make it go faster lol. It did sit for 5 years or so but if something is stuck it's not in the external linkage.

It does close to 8 at idle...sorry your stumped but it is what it is. I know I've been behind the wheel of more power and speed than you could ever dream of that also is what it is. The dress remark is just you feeling insecure and lashing out. It's just a tractor buddy.. relax

Well there is your answer...It has been sitting for five years. See old hydros build up kinetic energy from non use. So, when you start stroking that handle well...things start a happening so hang on for the ride! That's what I was always told. :biggrin2:

Lol. I doubt that all of that but whatever.
They won't go that fast. I've heard all this before from other people on here. If it goes 8 mph at an idle and faster than 10 wide open, I want to see the speedo on the truck following it. I've had a few that were faster than others. Had one I swore ran 12... but never checked it. They weren't made all that precisely, and some are just faster than others. It happens, but lets get real. A hydro can't go that fast unless it has been modified.

This is a hilarious thread! I'm getting a kick out of it! A speed racing 129. :ExtremeFunny:

Oh, I'm not stumped buddy. You are! I'm not the one trying to fix the tractor. :beerchug:

Cooperino, we are just having some fun. Maybe post a video and show us what is happening with the linkage and how fast it seems to be moving. :beerchug:

:IH Trusted Hand:

I guarantee it is not going 8 at idle. You would have to see that kind of mod
The engine would be lugging pretty hard also.

Ok, we've read the book. Now we want to see the movie! :popcorn:

No no no.. I will not be putting it back together to prove anyone wrong. I won't be making a video of how fast it goes "refer to previous statement" I really do not feel the need to prove anything to anyone here. I don't care what any of you guarantee or think you know what can or can't be when it comes to this. I operate all kinds of equipment daily and know when I am on a piece of equipment that is dangerous to operate. The fact that any of you have asked me to video myself doing something that I have already said is unsafe is ludicrous to me. I hope you don't go putting people who may know less in danger like this but it's apparent you most likely would since none of the people saying this worried about safety at the time. I will do my own investigating into this and repair as necessary before putting it back together and only run it after it is safe to do so. For any of you who said "oh its a left hand hydro and they are different" IDIOTS. I don't care what side the handle is on. Cub never made these tractors to act this way as I have stated several times. I may have been being jovial about the whole situation and laughing some because the tractor almost threw me off but if any of you can honestly tell me that these were built to be able to throw a 6'2 225 pound guy off at half throttle no matter how fast you move that lever or how far from neutral you push it I would be shocked. At this point I'm sure someone here will somehow rationalize a way to say yeah! they are suppose to do that... pffftt..

I get it that many of you here feel that since you have owned a bunch of cubs you think that if its never happened to you it just can't happen. Many of you think you have seen it all and nothing will ever be new to you. Well guess what none of you "know it all" Even all the people here combined do not know it all and furthermore have not seen everything there is to see. In this life when you stop learning and experiencing new things your dead.

Cooperino, man..... I get it. You've driven fast stuff, and you've worked on a lot of things. But you must not understand how these hydro's are put together. Listen, there is a swashplate inside that contols the speed but changing the stroke of the pistons on the pump. When at full speed in forward, or reverse, the swashplate comes into contact with the case of the hydro. It CAN'T go any farther. You can't make it faster. It can physically only move so far. The ONLY way to speed one up like you say this one is, is if you took the hydro apart, and ground off the back of the swashplate or the case. That's it. You can't do anything with the linkage, and nothing can break to make it faster. It has an internal mechanical limit. I'm sure that not all the CC tractors full forward lets the swashplate rest on the stop, and that is why some tractors are faster than others, but man...... it can't be doing what you say. It has to be that it just scares you and you think it's faster than it is. I'm sorry that makes you mad..... but it's fact.

Go ahead and tear it all apart. Let us know what you find. But you aren't going to find anything. All you will find is some worn out linkage. Fixing it will change the response, but not the speed unless you slow it down.

So how do you know the plate is not worn allowing it to move beyond intended travel?

LMFAO. Because it has a flat spot cast on it about 1.5" square that it hits. I've had a lot of hydro's apart. They don't wear. I've never had one apart that even had been hammered on. They don't wear that way. Besides, it would have to pound like 1/8" off the case before it would speed it up that much.

On the top speed issue Jon is correct. The Sundstrand manual specs show that at full forward the pump displacement equals motor displacement and you have a 1:1 ratio input to output. The output then goes into a 7:1 reduction gear which then goes into a 3.54 ring pinion gearset. So running through the numbers at 3600 input rpm we end up with an axle speed of 145 rpm. With a stock tire size at 23 inches that works out to 873 fpm or 9.92 mph. Without mods to increase pump output or some gearing changes that's what it is.

Now on the fast acceleration, if you are a 100% sure the external linkages are good then the only thing I can think of is the coil pins connecting the trunnion input shaft to the trunnion are loose letting the swashplate move farther than what the control is moving (have never seen this happen but anything is possible) . Hydros want to go full tilt naturally and the controls actually hold them back. Check the trunnion shaft at both ends to be sure they are pinned securely.

Real quick then I have to run... gotta go to church.

I've had those coil pins break internally on the hydro. It (swashplate) still can't go any farther. When they break, you can't center the pump and you have no neutral. It won't ever stay in neutral when you put it there, and it won't go faster. You just can't ever get the tractor to hold still. You put it in neutral, then it starts backing up. You move the lever again, it stops, but then creeps forward. If they are broke.... you wouldn't be able to stop it.

:TTWWP:

Got pics Jon?:biggrin2:

Not now, but I do have one out in the shop in pieces if I can find it.

What a slacker.
I would just do as the others said and tighten up the hydro linkage, repair or replace as necessary.
BTW I had prolly 20 of those runaway tractors and as I mentioned above it took care of it.
This part seems to never wear out. Some have a machined plate that fit in the slipper area some do not.

It does not "run away" If I am understanding the term run away to me would mean you push lever say .75" to start moving forward while it stays and holds at .75" run away would mean it gets faster and faster even though you did not move the handle more.. Thats not what its doing. I can maintain speed.. When i push it forward really slowly I can control it at any speed. At some point in the forward lever it feels like its going way faster than it ever should, by time I push the lever all the way forward its going so fast that it feels out of control. The steering is tight enough and feels fine at speeds im use to from other tractors. The other part of the issue is when I move the lever forward any faster than barely moving it the tractor will either lift the front wheels off the ground "on pavement" or spin the tires like mad on grass. My other tractors will all spin the tires if I am really aggressive with them but quickly get traction and stop spinning. This is happening when I am working the lever gently. It does this with the throttle anywhere above say 40% of WOT and up.

I knew it wouldn't go faster, was just thinking a loose swash plate would make for jerky control. If that's not the problem then I'm thinking Lew is on the right track about tightening up linkages. A little slop in each connection can add up to a lot at the far end.

Thanks for the pic Lew! Now I don't have to go dig it out. I was looking for engine parts the other day and found a hydro apart in a box.... I'd wondered where I'd put it. I've never organized the garage after I moved out of the shop.

I agree with loose linkages causing control issues, but he seems to think it has good control, it's just "fast". The left hand hydro tractors are just more "touchy" than the right hand ones.

Yes coop. If the spirol pin was cracked or broken it would be hard to control, but where you really notice it is when you try to put it in neutral. I've not ever had one break completely in half where you had no control. I'm sure it can happen.